#!/usr/bin/env python3
# encoding: utf-8
"""
last edited at 2019-8-18
by Stone at BlueNet
"""
import math

def dis(x1, y1, x2, y2):
    """Get distance between two points."""
    return math.sqrt((x1-x2)**2 + (y1-y2)**2)


if __name__ == '__main__':
    pass

